//accepted 
#include <cstdio>
#include <iostream>
using namespace std;
long long x, y;
int main(){
	//freopen("in.txt","r",stdin);//freopen("out.txt","w",stdout);
	
	while(cin>>x>>y){
		if(x>y)cout<<x-y<<endl;
		else cout<<y-x<<endl;
	}
	return 0;
}
